This rotary tar slurrifier invention is in the field of alternative fuels for use in diesel engines operated in our transportation industries. Specifically this invention is in the field of fuel particle in water slurry fuels, for use in medium and high speed diesel engines, derived from coal. With the possible exception of a few steam locomotives in railroad use, essentially all US surface transportation systems, railroad, tug & barge, highway truck, are powered with medium and high speed diesel engines, using largely distillate petroleum fuels as an energy source.
Experimental operation of diesel engines with pulverized coal particles suspended in water, coal water slurry, as fuels, have been carried out over a long period of time starting almost with the original development of the diesel engine. The most recent such diesel engine experiments, with coal water slurry fuels, have been sponsored by the US Department of Energy between about 1978 and 1993. Much of the experimental work was carried out by several American diesel engine manufacturers. These experimental results are summarized in the following publications together with the many references listed therein:                1) Coal Fueled Diesel Engines, 1993 Edited by J. A. Caton and H. A. Webb. ASME Publication ICE-Vol 19.        2) Coal Fueled Diesel Development A Technical Review, T. A. Ryan. ASME Paper No. 94-ICE-20, 1994.        In general acceptable diesel engine combustion and efficiency were obtained, using pilot injection of number two diesel fuel as pilot igniter fuel, in these experiments. The two principal problems were aggravated piston ring and cylinder liner wear, due to coal ash particle abrasion, and particularly, severe fuel injector nozzle wear. This severe nozzle wear was partially, though not fully, reduced, by combining the pilot fuel injection with the coal water slurry fuel injection through the same fuel injector, as described in the following reference:        3) A New System for the Delivery and Combustion Control of Coal Slurries in Diesel Engines, by G. Baranescu, SAE Technical Paper 890446, 1989.                    Efforts to improve combustion by using smaller and more numerous coal particles, in the coal water slurry fuel, yielded disappointing results, and this has been attributed to reagglomeration of the small coal particles into larger coal particles, following injection into the diesel engine cylinder, and prior to coal particle ignition therein. This reagglomeration problem can be avoided by dissolving atomizing gases into the water phase of a fuel in water slurry, at pressures well above engine cylinder pressures during fuel injection, as described in my following US patents:                        4) U.S. Pat. No. 7,281,500, Supplementary Slurry Fuel Atomizer and Supply System, Firey, 2007.        5) U.S. Pat. No. 7,418,927, Common Rail Supplementary Atomizer for Piston Engines, Firey, 2008.                    It has long been recognized that our very large domestic reserves of low cost coal offer a tentatively promising means for achieving the national energy independence, needed to escape our heavy dependence on petroleum imported from nations who use their nationalized petroleum resources as an economic and political tool to serve their interests. The world petroleum market has not been a truly free market for many years, and this situation has adversely affected the United States' economy. Past efforts to use coal as a fuel for surface transportation industries have been largely unsuccessful.                        